. The new medical world. A book for reference and consultation, containing a thorough description of disease, with the latest and best methods for its treatment . Lines to test the existence of Other lines to detect astigmatism. 264 THE NEW MEDICAL WORLD. is indistinct. The attempt to see near objects wearies the muscles,produces headache and perhaps pain in the eyes, or eye-strain. Re-mote objects may be seen by the hypermetropic eye distinctly withoutstrain, pain or weariness. Presbyopia.—(Old Sight).—In this condition the patient doesnot see well, because the cornea is flatten
. The new medical world. A book for reference and consultation, containing a thorough description of disease, with the latest and best methods for its treatment . Lines to test the existence of Other lines to detect astigmatism. 264 THE NEW MEDICAL WORLD. is indistinct. The attempt to see near objects wearies the muscles,produces headache and perhaps pain in the eyes, or eye-strain. Re-mote objects may be seen by the hypermetropic eye distinctly withoutstrain, pain or weariness. Presbyopia.—(Old Sight).—In this condition the patient doesnot see well, because the cornea is flattened and the lens does notrespond to the action of the ciliary muscle sufficiently to increase itsconvexity. The vision is poor for near objects. Astigmatism.—In this condition the cornea is not spherical, beingwarped, so to speak, and some rays of light entering the eye come toa focus sooner than others. This causes indistinct vision. Examinations show that persons suffering from astigmatism cansee horizontal lines more perfectly than perpendicular lines. Thelines here represented may be used to detect this affection. Linesare also arranged in a circle radiating from a center about the size ofa
Size: 1578px × 1584px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., book, bookcentury1800, bookdecade1890, booksubjectmedicinepopular
